Method of and apparatus for rolling rounds



V. E. EDWARDS.

METHOD OF AND APPARATUS FOR ROLLING ROUNDS. APPLICATION FILED NOV. 23.1914.

1,193,001; Patented Aug. 1, 1916 Bveniov VICTOR E. EDWARDS, OFWORCESTER, MASSACHUSETTS, ASSIGNOR TO MORGAN CON- STRUCTION COMPANY, OFWORCESTER, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

METHOD OF AND APPARATUS FOR ROLLING ROUNDS.

Specification of Letters Patent.

Patented Aug. i, was.

Application filed November 23, 1914. Serial N 0. 873,463.

To all whom it may concern:

Be it known that I, VIoToaE. EDWARDS, a citizen of the United States,residing at Worcester, in the county'of Worcester'and Commonwealth ofMassachusetts, 'have invented a new and useful Improvement in Methods ofand Apparatus for Rolling Rounds,.of which-the following, taken inconnection with the accompanying drawings, is a specification. I

The present invention relates to the production in a rolling mill ofbars of circular cross section known as rounds, and the said inventionresides in a new and improved methodof and. apparatus for finishingrounds, whereby the accuracy in section of hand rounds is obtained,together with the high output and correspondingly low cost of guiderounds.

My present invention aims to combine all the advantages of the two knownmethods,

above enumerated, in the production of accurate rounds at a high rate ofoutput. The following description, taken in connection with theaccompanying drawings, will serve to illustrate the principlesunderlying the production of rounds according to the method, and by theapparatus of my invention, the features of novelty being set forth 30 iin the annexed claims.

In the said drawings, Figure 1 is a diagrammatic representation .ofsomuch of an arrangement of rolhng mill apparatus as sentation .of theseveral cross sectional shapes imparted to the rod or bar, in theproduction of a round by the present invention. Fig. 3 is a diagrammaticrepresentationillustrating the method of producing hand rounds, andFig.- 4 is a diagrammatic representation illustrating the method ofproducing guide rounds.

Similar reference characters refer to similar parts throughout thedifferent figures.

.In the processpf producing so-called hand rounds the billet is reducedto an approximate round, slightly larger than the finished size, and isthen introduced two or more times, by hand, tothe same finishing passformed in a pair of rolls. Such a finishing pass is indicated in Fig. 3.It is well known that a bar even slightly outof round has a pronouncedtendency to turn down, when subjected to a rolling operation,

so that its major axis shall be horizontal.

In finishing a bar by means. of the pass shown in Fig. 3, of course themajor axis must be kept vertical. In producing a round by this method,theoperator firmly grasps the rear end of the bar with a pair of tongs,and pushing the other end into the grooved rolls, follows the bar asitisrolled, carefully watching it and instantly opposing any tendency of thebar to turn down either to the right or to the left. He

sequent introductions, the bar is given a quarter turn about its axisin'order that the slight fins which have formed thereon'by the squeezingout of the metal, between the parting of the rolls and into the tailoredcavities 1, may be eliminated. This method of finishing rounds, whileconducive to the production of rounds of excellent accuracy, is subjectto extremely serious, in fact almost prohibitive, limitations, by reasonof its very low output and consequently high producing costs, owing tothe very low speed at which the rolls must be run, and owing to thenecessity for employing very short bars to avoid turning down in spiteof the efforts of the operator.

In the well-known process of producing so-called guide rounds, the bargoes but once through the finishing pass. It is presented to thefinishing pass in'the form of an approximate ellipse, the ma or axis ofwhich, in high tonnage mills, is usually made not less than fifty percent. more than its minor axis. This distinct ellipse has, of

course, a strong tendency to turn down,

which tendency is resisted'by side guides 2 placed close to the rolls.Such a finishing pass 3 and such side guides 2 are indicated in Fig. 4.The ellipse must be decidedly flat in order to give the guidessuflicient leverage to enable them to hold the ellipse from turning downor from jamming in the guides. When using fiat ellipses with suitableside guides, there is no known limit to the length of the bars which maybe finished or to the speed at which the rolls may be run. Thiscombination of long lengths and high speed permits large outputs at lowproducing costs. .These low producing costs explain why probably overninety-five per cent. of the rounds under two inches in diameter arefinished on guide mills. But it has not heretofore been possible tomaintain accurate sections on guide rounds.

Referring again to Fig. 4:, I have said that the ellipse must bedecidedly flat in order that the guides 2 may hold it from turning down.In common practice in high tonnage mills, the major axis of the ellipseis seldom less than fifty per cent. greater than the minor axis, and theminor/axis is seldom,

greater than twenty totwenty-five per cent. less than the diameter ofthe desiredround. In other words, the transition from the ellipse to theround involves a side spread approximating twenty to twenty-five percent. of the required diameter, as shown at 4, 4 in Fig. 4, over whichthere is almost no control, and yet it is required of the mill tomaintain the desired diameter within one per cent. It is, of course,obvious that a very slight change in size, shape or temperature of theelliptical section in any'bar, or in any part of the length of any bar,will produce a serious difference in the amount of side spread, and thediameter of the bar measured horizontally will be objectionably more orless than it should be. I

The makers of rounds are constantly striving to maintain generoustolerances between maximum and minimum diameters, which will permit themtdmake large outputs with small percentage of rejections and,consequently, at low producing costs. On the other hand, the users ofthese rounds are as constantly insisting on greater accuracy of sectionas affecting their cost of fabrication.

The present invention provides for the virtual elimination of the abovedescribed errors arising in the production of guide rounds, withoutsacrificing the high output and low producing costs of such a mill, andthe apparatus by which this result is attained is shown in Fig. 1.

In F ig..l.is shown, at the left hand side, a series of roll housings 5,6 and 7, the same representing diagrammatically the finishing end of amill adapted for the production of guide rounds according to the methodhereinbefore described. Thepath of the material is indicated by thebroken line 8, and the cross sectional shape and the orientation of thesame both prior to andafter its passage through the successive passes ofthe rolls is indicated by the several cross sectional representations onopposite sides of the passes of the rolls. As shown, the final productof this mill is an approximate round, and the said round, in thecarrying out of this invention, is purposely given a cross sectionalarea slightly 1n excess of the cross sectional area of the round whichit is desired eventually to produce.

Referring to Fig. 2, the outer circle 9 indicates the average section ofthe approximate round produced by the guide mill at the left hand sideof Fig. 1, and the slightly smaller circle 10 indicates the section of"round which it is desired to produce by the present process. Theinvention contemplates the continuous reduction of the round 9, to formthe round 10, with the least opportunity for error to arise by reason ofthe successive changes in the shape of the material during saidreduction. To do this it is proposed to change the approximate round 9into an approximate ellipse, as indicated at 11, Fig. 2, the minor axisof said approximate ellipse being but slightly less than the desireddiameter of the finished round, and then instantly to change thiselliptical section to the finished round. It will be seen that by reasonof the relative roundness of the ellipse 11, the relatively slightreductions required, and the correspondingly relative slight sidespread, indicated at 12, Fig. 2, which must be effected, the possibleerror in the cross sectional shape and area of the finished round, dueto uncertain side spread, is reduced to a minimum.

In order to carry out the steps of my method above set forth, provisionis made for the formation of a free loop 13 in the bar 9 after the sameis led to the pass in a pair ofvertica-l rolls 1%, Fig. 1, which impartthereto an elliptical section having the characteristic above set forth,namely, a minor axis only slightly shorter than its major axis. Anellipse 11 of such proportions is incapable of being held from axialturning by the use of guides,.by reason of its close approach to acircle, hence it is necessary to dispose the horizontal rolls 15, whichhave a. circular pass of the desired crosssectional area of the finishedround, inimmediate juxtaposition to said vertical rolls 14. Thereforethe ellipse 11, emerging continuously from the pass between the rolls14, is immediately subjected to a change in form and area by passagebetween the rolls 15, there being no opportunity for the elliptical barto turn in the very limited distance between the passes of the two setsof rolls. It will beclear from Fig. 2 that the amount of side spread,indicated at 12, Fig. 2, is very slight; furthermore, that the actualreduction in cross sectional area, in rolling from the ellipse 11 to theround 10 is much less than in the previously described method ofproducing guide'rounds. The product emerging continuously from the finalpass between the rolls 15 is, -therefore, necessarilv more accurate indimension than the prodfinal transition from an ellipse to a. round 7 isaccompanied, not only by a relatively high reduction in cross sectionalarea,'but

also by a very considerable degree of side spread.

It is to be understood that slightly ellip- I tical, and similar termsused hereinafter in the appended claims, refer to a cross sectionalshape of bar which is not sufficiently flat to permit of holding up bymeans of side guides. v

By my invention it is feasible to use a finishing ellipse that shallhave a/ side spread from the finishing oval to the finished round lessthan one-fifth that now common in finishing guide rounds, hence. it. isreasonable to expect finished rounds with much less variation in theirwidth than formerly. In other words, it will be seen that I havecombined the accuracy of hand rounds with the high output andconsequently low cost of guide rounds.

I claim,

1. A method of rollinrounds, includ ing the producing 0 an approximateround of slightly larger section than the required round, rolling saidapproximate round to an ellipse whose minor axis is slightly less thanthe diameter of the required round, and reducing said ellipse to therequired-round.

2. A method of rolling round, including the producing by a'continuousrolling operation of an approximate round of slightly. greater sectlonthan the required round, continuously rolling said approximate round toan ellipse whose minor axis is slightly less than the diameter of therequired round and producing from said ellipse by a continuous rollingoperation a round of the required diameter.

3. A method of rolling rounds of an accurate section, including thecontinuous feeding of an approximate round of a section slightly greaterthan the section re quired to a rolling mill pass adapted to change saidapproximate round 'to an ellipse whose minor axis is slightly less thanthe required diameter, and passing said ellipse continuously betweenrolls adapted to change said ellipse to a round of the requireddiameter.

4. A method of rolling metal bars to accurate circular section,including the production by a continuous rolling operation of anapproximate round of slightly greater section than the final sectiondesired, continuously rolling said approximate round to form anapproximate ellipse having. a minor axis slightly less than the requireddiameter, providing for a free overfeed loop of the metal between theabove mentioned rolling operations, and continuously reducing saidapproximate ellipse to a round of the required diameter.

- 5. A three stand continuous mill for rolling rounds, comprising afirst stand to produce an approximate round slightly larger than thedesired section, a second stand to reduce said approximate round to anapproximate ellipse, and a third stand to reduce said approximateellipse to the finished round, the last two stands of rolls having theiraxes at right angles to each other and being in such juxtaposition as toprevent the approximate ellipse from turning down while between saidstands and the first and second stands belng separated to permit a freeoverfeedloop between them.

6. Means for continuously finishing a round from a guide round ofslightly larger section, comprising a two pass continuous mill, havingthe two pairs of reducing rolls at right anglesto each other and in suchjuxtaposition as to prevent the metal from turning axially while betweensaid pairs of rolls."

' 7. In apparatus for finishing metal bars to accurate circular section,the combination with a guide mill for producing an approximate round ofslightly larger section than the required section, of a two-:passcontinuous sizing mill having its two pans of rolls at right angles toeach other and in such juxtaposition as to prevent axial turn. ing ofthe metal while between said pairs of rolls and a space for permitting afree overfeed loop between said guide mill and sad sizing mill.

Dated this twenty VICTGR E. EDWARDS first day of November WitnessesWILLARD A. WINN, PAULINE Bass.

Corrections in Letters, Eaterit No.1 ,193,001.

it is herebj certified that in LetterePatent No. 1,193,001, grantedAugust 1, 1916, inpon the applieetieh of Victor E. Edwards, ofWoreester, Massachusetts, 1'0 ah inrprovenient in Metheds qiandApparatus for Rolling Reunds, errors appear in the printedspecifi'rcation requiring correction as follows: Page 1, line 6 8, forthe word clesed readc los ej page 3, line 1 3, claim 2, for the Wordround read 'ro'emdgend that the said Letters Patent shouldbe'read withthese correct ions therein that the same may corlform to the record ofthe case in the Patent Ofliee.

' Signed and sealed this 29th day of August, 4A.,D., 1916.

F. W. H. CLAY, -v

[smirk] Acting Uommwiomr of Patents

